A radio frequency (RF) power amplifier is a type of electronic amplifier used to convert a low-power radio-frequency signal into a larger signal of significant power. The RF power amplifier typically comprises multiple power cells. Each of the power cells includes one or more power transistors designed to optimize efficiency, linearity, output, and cost of the power amplifier.
One commonly-used application of the RF power amplifier is to drive a transmitting antenna of a transmitter or transceiver of a communication device for voice and data communication. Since mobile communication devices such as cell phones are increasingly operating under multiple modes and multiple bands (MMMB) during communication, where most of integrated circuits (ICs) in the mobile communication devices are manufactured using complementary metal oxide semiconductor (CMOS) technology, the cost and performance of the power cells manufactured with CMOS technology and used by the RF power amplifiers in the mobile communication devices are becoming very important.